The present invention generally relates to an electrical system for detecting and correcting loss of control of a vehicle pulling a fifth wheel trailer, including wheel slipping or skidding, or trailer pitch or yaw.
Driving a motor vehicle properly and safely requires that a motorist be trained and licensed. The training of motorists can involve behind-the-wheel experiences as well as classroom time. Training for drivers of automobiles is decidedly different than that for drivers of tractor-trailers, buses and recreational vehicles. This latter group must be concerned about the proper way to maneuver these larger vehicle and any trailers that they might be towing especially during inclimate weather conditions. It is during those conditions that the majority of highway accidents occur. Many of these accidents could be prevented if driver training was completed and motor vehicles were fitted with safety equipment.
It is a common experience with automotive vehicles for excessive wheel slip or spinning to occur during vehicle acceleration. This happens when the operator causes an extremely high engine torque to be delivered to the driven wheels such that the frictional forces between the tire and the road are overcome. In the event that the road surface is slippery a moderate engine torque can cause such slipping. While a small amount of slip between the tire and road surface is necessary to achieve a driving force, an excessive slip results in reduction of effective driving force or traction.
During vehicle acceleration slipping between the driven wheels and the road surface is always present, otherwise no tractive force would be developed. The amount of slipping increases as driving torque applied to the wheels increases until the wheel traction reaches maximum and thereafter traction decreases with further increases of wheel slip. The point of maximum traction varies according to road conditions.
Ice is a particularly dangerous hazard on any type of road or highway. Those who drive large trucks with trailers attached to them, often referred to as fifth wheel trailers, are especially prone to accidents during icy conditions. Drivers should proceed in a careful manner. They should maintain a steady, low speed and use caution when applying brakes or taking curves. If any of these precautions are neglected, they can result in a jackknife experience that can cause property damage, injury, or even death.
Accordingly, there is a continuing need for a system for detecting and correcting such loss of vehicle control. The present invention fulfills this need and provides other related advantages.
The present invention resides in an electrical system for detecting and correcting loss of control, including wheel slipping or skidding, or a vehicle pulling a fifth wheel trailer. The system comprises a first wheel movement sensor operably disposed adjacent to a driven wheel of the vehicle, and producing an electrical signal as a function of drive wheel rotational speed. A second wheel movement sensor is similarly disposed adjacent to a non-driven wheel of the vehicle and produces an electrical signal as a function of non-driven wheel rotational speed. A computer is an electrical connection with the wheel sensors for receiving and comparing the signals produced by the wheel sensors. A disengaging mechanism controlled by the computer for disengaging a drive line of the vehicle, typically from a vehicle clutch, when the driven wheel rotational speed exceeds the non-driven wheel rotational speed by a predetermined amount. In a particularly preferred embodiment, the disengaging mechanism is controlled by means of a cruise control system of the vehicle, which is operably connected to the computer.
In a particularly preferred form of the invention, a trailer pivot sensor produces an electrical signal as a function of trailer pitch and yaw. A steering wheel position sensor may also be incorporated to track the position of the steering wheel in comparison to the trailer position. A temperature sensor may be associated with the vehicle for monitoring ambient temperature. These components are electrically connected to the computer, and information may be provided to a monitor connected to the computer and disposed within a cab portion of the vehicle. Preferably, the monitor includes a tachometer.
Thus, when the electrical system of the present invention detects loss of control due to wheel slipping or skidding, or trailer misalignment due to improper wheel speed, the drive line of the vehicle is at disengaged, such as by disengaging the clutch of the vehicle, allowing the driven and non-driven wheels to match one anothers road speed and correct any wheel slipping or skidding that may cause trailer jackknifing or the like.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.